Method for manufacturing rupture disks

ABSTRACT

An improved method of manufacturing a rupture disk containing one or more scores or perforations from a sheet metal section comprising the steps of cutting the sheet metal section into a disk, forming a concave-convex dome in the disk by applying pressurized fluid to one side thereof, and then forming one or more scores or perforations in the concave-convex dome of the disk while continuing to apply pressurized fluid thereto. Automated apparatus for carrying out the method of the invention is also provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a method and apparatus formanufacturing rupture disks, and more particularly, but not by way oflimitation, to an improved method and apparatus for manufacturingrupture disks containing one or more scores or perforations from sheetmetal sections.

2. Description of the Prior Art

Many fluid pressure relief devices of the rupturable type have beendeveloped and used heretofore. Commonly, such rupturable pressure reliefdevices include a rupture disk supported between a pair of supportingmembers or flanges which are in turn connected to a relief connection ina vessel or system containing fluid pressure. When the fluid pressurewithin the vessel or system exceeds the design rupture pressure of thedisk, rupture occurs causing excess fluid pressure to be relieved fromthe vessel or system.

Various types of rupture disks and rupture disk assemblies have beendeveloped and used which fall within three general categories, i.e.,those that rupture in tension known as "conventional" rupture disks,those that reverse and then rupture known as "reverse buckling" rupturedisks and composites of both the conventional and reverse bucklingtypes. Composite rupture disk assemblies generally include one or morerupture disks combined with one or more perforated members such asvacuum supports, protection members, members which tear or rupture whena primary rupture disk ruptures, etc. While some rupture disks andcomposite assemblies are flat, most include an annular flat flangeportion to facilitate clamping between supporting members or flangesconnected to a concave-convex dome portion which ruptures when excessfluid pressure is exerted on the disk. In the operation of a reversebuckling rupture disk, the fluid pressure is exerted on the convex sideof the dome portion of disk, and upon failure, the dome portion reversesand then ruptures. Fluid pressure is exerted on the concave side ofconventional rupture disks and the disks rupture in tension.

Metal rupture disks of both the reverse buckling type and conventionaltype have heretofore included one or more scores on a surface of theconcave-convex portion which create lines of weakness so that uponrupture of the disk, the concave-convex portion tears along the lines ofweakness and opens with little or no fragmentation of the metal. Variousmethods of manufacturing scored rupture disks have heretofore beendeveloped. For example, a method of manufacturing reverse bucklingscored disks is disclosed in U.S. Pat. No. 3,921,556 issued Nov. 25,1975 and assigned to the assignee of the present invention. While suchmethod as well as other methods have been used successfully formanufacturing scored reverse buckling rupture disks, because ofdeformation and stresses which are produced in the disks, a number ofreforming and annealing steps have heretofore been required to producerupture disks having desired operational characteristics. Generally, inall of the heretofore used methods of manufacturing scored or perforatedrupture disks, the stresses and deformation produced when forming thescores or perforations have brought about less than optimum operationalcharacteristics or require additional manufacturing steps.

By the present invention an improved method and automated apparatus forcarrying out the method are provided for manufacturing scored andperforated rupture disks of the conventional, reverse buckling andcomposite types wherein deformation and stresses in the disks due to themanufacturing process are reduced and all or part of the time-consumingand expensive reforming and annealing procedures previously required areeliminated.

SUMMARY OF THE INVENTION

By the present invention there is provided an improved method ofmanufacturing a rupture disk containing one or more scores orperforations from a sheet metal section comprising the steps of cuttingthe section into a disk, forming a concave-convex dome in the disk byapplying pressurized fluid to one side thereof, and forming the one ormore scores or perforations in the concave-convex dome of the disk whilecontinuing to apply pressurized fluid thereto. Automated apparatus forcarrying out the method is also provided.

It is, therefore, an object of the present invention to provide animproved method and apparatus for manufacturing rupture disks containingone or more scores or perforations from sheet metal sections.

A further object of the present invention is the provision of a methodand apparatus for manufacturing scored rupture disks, both of theconventional and reverse buckling types, wherein fewer stresses and lessdeformation of the metal results as a consequence of the manufacturingprocess.

Another object of the present invention is the provision of a method andapparatus for manufacturing reverse buckling scored rupture diskswherein all or at least a part of the reforming and annealing stepsheretofore required for producing such disks with required operationalcharacteristics are eliminated.

Yet another object of the present invention is the provision ofautomated apparatus for manufacturing rupture disks containing one ormore scores or perforations.

Other and further objects, features and advantages of the presentinvention will be readily apparent to those skilled in the art upon areading of the description of preferred embodiments which follows whentaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partly sectional side elevational view of the apparatus ofthe present invention.

FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1.

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 1.

FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 1.

FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 1.

FIG. 6 is a cross-sectional view taken along line 6--6 of FIG. 1.

FIG. 7 is a side view of a portion of the apparatus of FIG. 1.

FIG. 8 is a cross-sectional view taken along line 8--8 of FIG. 7.

FIG. 9 is a schematic view of the apparatus of FIG. 1 including thehydraulic circuits, valves and other equipment which are a part of theapparatus.

FIG. 10 is a partly sectional side elevational view of the apparatus ofthe present invention which is similar to FIG. 1 except that a sheetmetal section has been clamped in the apparatus and cut into a disk.

FIG. 11 is a partly sectional side elevational view of the apparatus ofthe present invention which is similar to FIG. 10 except that the sheetmetal section has been formed and scored by the apparatus.

FIG. 12 is a perspective view of a scored rupture disk manufactured inaccordance with the present invention.

FIG. 13 is a top plan view of the rupture disk of FIG. 12.

FIG. 14 is a perspective view of a scored rupture disk having adifferent score pattern formed thereon than that shown in FIGS. 12 and13.

FIG. 15 is a perspective view of a scored rupture disk having yetanother score pattern formed thereon.

FIG. 16 is a perspective view of one form of rupturable support memberincluding perforations which can be manufactured in accordance with thepresent invention.

FIG. 17 is a perspective view of an alternate form of rupturable memberincluding perforations.

FIG. 18 is a perspective view of yet another form of rupturable member.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to the drawings, and particularly to FIGS. 1-6, theautomated apparatus of the present invention for manufacturing rupturedisks containing one or more scores or perforations from sheet metalsections is illustrated and generally designated by the numeral 10. Theapparatus 10 is formed of metal and includes a rectangular base 12having a pair of rectangular vertical side supports 14 and 16 attachedto opposite end portions thereof. A circular opening 18 is centrallypositioned in the base 12 and a cylindrical pedestal 20 is attached tothe base 12 over the opening 18. Positioned on opposite sides of thepedestal 20 and attached to the base 12 are conventional hydrauliccylinders 22 and 24 having vertically extending lever arms 26 and 28,respectively.

The lever arms 26 and 28 of the hydraulic cylinders 22 and 24 arerigidly attached to a rectangular platform 30. The platform 30 is of asize corresponding with the base 12 and the opposite end portions 32 and34 of the platform 30 extend over the upper ends of the supports 14 and16. Three spaced apart vertical guide pins 36 are attached to the endportion 32 of the platform 30 which slidably extend into complementarybores 38 disposed in the support 14. In a like manner, three verticalguide pins 40 are attached to the end portion 34 of the platform 30which slidably extend into complementary bores 42 disposed in thesupport 16.

The platform 30 includes a circular opening 44 (FIG. 1) disposedtherein, and attached to the lower side of the platform 30 around theopening 44 is a clamping and cutting assembly generally designated bythe numeral 46. As best shown in FIGS. 1, 4 and 5, the assembly 46 iscomprised of a fixed cylindrical cutting member 48 which is rigidlyattached to the platform 30 by a plurality of cap screws 50. The cuttingmember 48 includes an inwardly extending flange portion at the bottomthereof forming an upwardly facing annular shoulder 52 interiorlythereof.

Slidably disposed within the cutting member 48 is a cylindrical clampingmember 54 which includes an upper outwardly extending flange portionwhich forms a downwardly facing annular shoulder 56. The clamping member54 is of a vertical size such that it is free to slide vertically withinthe cutting member 48 between a lowermost position whereby the annularshoulder 56 thereof abuts the annular shoulder 52 of the cutting member48 and an uppermost position whereby the upper annular end 58 of theclamping member 54 abuts the lower side of the platform 30. The lowerannular end 60 of the clamping member 54 includes at least two andpreferably three downwardly extending locating hole punches 62 spaced inpredetermined relationship thereon.

As shown in FIGS. 1 and 4, the upper annular end 58 of the clampingmember 54 includes an annular recess 64 formed therein within which aconventional O-ring 66 is disposed. In addition, a plurality of springs68 are positioned in complementary opposing recesses formed in the ends58 of the clamping member 54 and the platform 30. The springs 68 urgethe clamping member 54 to its lowermost position with respect to thecutting member 48 as illustrated in FIG. 1.

Removably positioned on top of the cylindrical pedestal 20 is acylindrical rupture disk forming die 70. As shown in FIGS. 1, 2 and 3,the cylindrical die 70 is removably held in alignment with the clampingand cutting assembly 46 on the pedestal 20 by a pair of clips 72 and apair of alignment pins 74. The alignment pins 74 are attached to thebottom face of the die 70 and extend into complementary bores disposedin the pedestal 20. The clips 72 include tongue portions 76 which extendinto complementary grooves in the die 70 and the clips 72 are held tothe pedestal 20 by bolts 78.

The upper face of the die 70 has a forming configuration comprised of anouter annular flat portion 80 (FIGS. 1 and 3) surrounding an innerdish-shaped recess 82. Disposed in the annular flat portion 80 of thedie 70 are three openings 84 of complementary position and size with thelocating hole punches 62 of the clamping member 54. The openings 84communicate with enlarged passageways 86 which extend from the openings84 downwardly through the die 70 to the bottom face thereof where theycommunicate with the central opening in the cylindrical pedestal 20which in turn communicates with the opening 18 in the base 12. Anotherpassage 88 is disposed vertically through the die 70 from the recess 82to the bottom face thereof whereby the recess is communicated with theopening in the cylindrical pedestal 20.

Attached to the top of the platform 30 are a pair of spaced apartvertically positioned rectangular support members 90 and 92. The topends of the support members 90 and 92 are in turn attached to ahorizontally positioned rectangular support member 94. A hydrauliccylinder 96 is attached to the bottom side of the member 94 whereby thelever arm 98 of the cylinder 96 extends vertically downwardly. Attachedto the arm 98 is a horizontally positioned rectangular striker plate 100(FIGS. 1 and 6) and attached to the bottom side of the plate 100 is avertically positioned elongated cylindrical ram 102 (FIGS. 1 and 4)which slidably extends through the circular opening 44 in the platform30.

An annular seal unit 104 is bolted to the top surface of the platform 30around the opening 44 therein by a plurality of bolts 106. The seal unit104 includes an annular recess 108 positioned adjacent the outsidesurface of the cylindrical ram 102 and a conventional O-ring 110 isdisposed in the recess 108.

As shown in FIGS. 1 and 5, attached to the downwardly facing circularend of the ram 102 by a plurality of cap screws 112 is a score formingblade assembly 114 which includes a circular base member 116 to which ablade member 118 of cross configuration is attached. The base member 116includes a vertical passage 120 extending therethrough which aligns andcommunicates with a vertical passage 122 in the cylindrical ram 102. Thevertical passage 122 intersects and communicates with a horizontalpassage 124 which extends through a side of the ram 102 and is threadedfor receiving a conventional fitting to which a hose is attached (notshown).

Referring now specifically to FIGS. 1, 6, 7 and 8, a pair of microbarassemblies 130 and 132 are attached to the platform 30 on opposite sidesof the ram 102 and are positioned parallel to each other and to the endsof the striker plate 100. The microbar assemblies 130 and 132 functionin combination with the striker plate 100 to limit the downward movementof the ram 102 and blade assembly 114 attached thereto.

The microbar assemblies 130 and 132 are identical and the followingdescription of the assembly 132 applies equally to the assembly 130. Asbest shown in FIGS. 7 and 8, the microbar assembly 132 is comprised of abase member 134 which includes an upwardly facing rectangular recess 136extending over its entire length. The bottom surface 138 of the recess136 is inclined with respect to the member 134 and an elongatedsubstantially rectangular bearing member 140 is disposed in the recess136 of the base member 134. The bottom surface 142 of the member 140which is in contact with the bottom surface 138 of the recess 136 isinclined similarly to the surface 138 whereby the top 144 of the member140 remains parallel to the bottom of the base member 134 when themember 140 is moved laterally with respect to the base member 134.However, as will be understood, when the member 140 is moved to theright with respect to the base member 134, the distance between the topsurface 144 thereof and the bottom of the base member 134 increases.Conversely, when the member 140 is moved to the left with respect to thebase member 134, the distance between the surface 144 thereof and thebottom of the base member 134 is decreased.

Semicircular laterally extending grooves 146 and 148 are disposed in theadjacent surfaces 138 and 142 of the base member 134 and bearing member140, respectively, and the groove 148 includes threads while the groove146 does not. A threaded shaft 150 is disposed within the semicirculargrooves 146 and 148, the threads of which engage the threads of thegroove 148, and a knob 152 for rotating the shaft 150 is attached to oneend thereof. The shaft 150 is prevented from moving with respect to thebase member 134 by a flange portion 154 at one end thereof and acontinuous annular recess 156 at the other end thereof into which aprotuberance 158 in the semicircular groove 146 of the member 134extends. As will now be apparent, when the shaft 150 is rotated byrotating the knob 152, the member 140 is moved laterally eitherincreasing or decreasing the overall height of the assembly 132.

Referring now to FIG. 9, the apparatus 10 is schematically illustratedin conjunction with the hydraulic fluid conduits, valves, controls andpump for operating the hydraulic cylinders 22, 24 and 96 and with theconduits and valves for causing pressurized fluid to flow through and beexhausted from the passages 122 and 124 of the ram 102 and the passage120 of the blade assembly 114. More specifically, the upper hydraulicfluid ports of the hydraulic cylinders 22 and 24 are communicated with aheader 170 by conduits or hoses 172 and 174, respectively. The lowerports of the cylinders 22 and 24 are communicated with a header 176 byconduits or hoses 178 and 180, respectively. The headers 170 and 176 arecommunicated with the ports of a conventional solenoid operatedhydraulic control valve 182 by conduits 184 and 186, respectively.

The upper port of the hydraulic cylinder 96 is connected by a conduit orhose 188 to a port of a conventional solenoid operated hydraulic fluidcontrol valve 192. The lower port of the cylinder 96 is connected toanother port of the control valve 192 by a conduit 194.

A conventional hydraulic fluid pump 196 is provided the inlet connectionof which is connected by a conduit 198 to a hydraulic fluid accumulatorand return system (not shown, but designated by the symbol ␣). Thedischarge of the pump 196 is connected by a conduit 200 to aconventional hydraulic fluid pressure regulator 202, and a conduit 204leads hydraulic fluid from the pressure regulator 202 to the hydraulicfluid inlet port of the valve 182. A conduit 206 connected to theconduit 204 leads hydraulic fluid to the inlet port of the valve 192.

A conduit 208 connects a port of the valve 182 to the hydraulic fluidreturn system and a conduit 210 connects a port of the valve 192 to thereturn system. A conduit 212 is connected to the conduit 200 and to thereturn system, and a solenoid operated valve 214 is disposed in theconduit 212. Conventional hydraulic fluid pressure switches 216, 217 and218 are connected to the conduits 206, 174 and 188, respectively.

A conduit 200 leads pressurized fluid, such as pressurized air, from asource thereof to a solenoid operated valve 202. A conduit or hose 204leads the pressurized fluid from the valve 202 to the opening 126 in theram 102 which is communicated with the passages 122, 124 and 120previously described. A conduit or hose 206 is connected to the conduitor hose 204 and to a solenoid operated shutoff valve 208. The valve 208is in turn connected by a conduit 210 to a flow restrictive orificeassembly 212. The assembly 212 is in turn communicated to the atmosphereor a vent by a conduit 214.

OPERATION OF THE APPARATUS 10

As will be understood by those skilled in the art, the operation of theapparatus 10 is controlled by a conventional electric control systemwhich can in turn be operated manually or operated by a computer, etc.The electric control system operates the solenoids of the hydrauliccontrol valves and the other valves described herein which in turncontrol the operation of the hydraulic cylinders 22, 24 and 96 and theapplication of pressurized fluid or the exhausting thereof. Morespecifically, the apparatus 10 is ready to commence the manufacture of ascored or perforated rupture disk from a sheet metal section as it isshown in FIGS. 1 and 9. More specifically, referring to FIG. 9 hydraulicfluid is pumped from the hydraulic fluid return and accumulator systemby the pump 196 through the conduit 198 and into the conduit 200. Theconduit 200 leads the hydraulic fluid to the pressure regulator 202which controls the hydraulic fluid pressure at a predetermined level.From the pressure regular 202, hydraulic fluid flows by way of theconduit 204 to the control valve 182 which routes the hydraulic fluid byway of the conduit 186 through the header 176 and the conduits 178 and180 into the lower ports of the cylinders 22 and 24 which causes theplatform 30 and the apparatus attached thereto to be moved upwardly awayfrom the die 70. The upper ports of the cylinders are communicated bythe conduits 172 and 174, the header 170 and the conduit 184 to thehydraulic fluid return system by way of the valve 182 and the conduit208.

In a like manner, hydraulic fluid flowing to the control valve 192 byway of the conduit 206 connected thereto is routed to the lower port ofthe hydraulic cylinder 96 by way of the conduit 194 and hydraulic fluidis exhausted from the upper port thereof by way of the conduit 188, thevalve 192 and the conduit 210 to the return system which causes theplate 100 and ram 102 to be moved upwardly by the hydraulic cylinder 96.

The manufacturing process is begun by placing a substantially squaresheet metal section 300 (FIGS. 1 and 3) on the rupture disk forming die70, i.e., on the upwardly facing forming face of the die 70. As will beunderstood, the sheet metal section 300 is generally cut from a largersheet, it is flat and it can be formed of any of a variety of metalsdepending upon the particular application in which the rupture diskmanufactured therefrom is to be used. Generally, the particular metalused and the thickness thereof are predetermined by prior experience orby trial and error.

After placing the sheet metal section 300 on the rupture disk formingface of the die 70, the hydraulic fluid control valve 182 is reversedwhereby hydraulic fluid flows from the valve 182 through the conduit184, through the header 170 and through the conduits 172 and 174 intothe hydraulic cylinders 22 and 24 by way of the upper ports thereof.This in turn causes the pistons within the hydraulic cylinders to movedownwardly and hydraulic fluid to flow from the cylinders 22 and 24 byway of the lower ports therein, the conduits 178 and 180, the header 176and the conduit 186 to the valve 182 and into the hydraulic fluid returnsystem by way of the conduit 208.

The downward movement of the pistons within the hydraulic cylinders 22and 24 moves the lever arms 26 and 28 thereof and the platform 30attached thereto downwardly. The platform 30 is maintained in properalignment by the guide posts 36 and 40 which move downwardly within thebores 38 and 42 in the support members 14 and 16. As the platform 30moves downwardly, the clamping and cutting assembly 46 moves towards thedie 70 and the sheet metal section 300 positioned thereon. The threepunches 62 (FIG. 1) extending from the annular face 60 of the clampingmember 54 first come into contact with the sheet metal section 300 asthe assembly 46 moves downwardly and the punches 62 punch locating holesin the section 300. The circular metal parts punched from the section300 when the locating holes are formed therein drop through the passages86 in the die 70 and through the interior of the pedestal 20 and theopening 18 in the base 12. As the platform 30 and the assembly 46continue to move downwardly, the annular clamping face 60 of theclamping member 54 contacts the sheet metal section 300 and rigidlyclamps it against the annular flat portion 80 of the forming face of thedie 70. The continued downward movement of the platform 30 causes thesprings 68 between the clamping member 54 and platform 30 to becompressed and the cutting member 48 to continue its movement towardsthe die 70. The external diameter of the cylindrical die 70 is slightlyless than the internal diameter of the cylindrical cutting member 48 sothat when the bottom face of the cutting member 48 contacts the portionsof the sheet metal section 300 overlapping the periphery of the formingface of the die 70, the continued downward movement of the cuttingmember 48 causes the overlapping portions of the section to be shearedtherefrom. When the hydraulic cylinders 22 and 24 have moved theplatform 30 to its lowermost position, the clamping face 60 of theclamping member 54 is positioned against the section 300 which is inturn clamped against the flat annular portion 80 of the forming face ofthe die 70. In addition, the lower portion of the cutting member 48overlaps an upper portion of the die 70, all as shown in FIG. 10.

The hydraulic fluid pressure switch 217 (FIG. 9) attached to the conduit174 senses the pressure of the hydraulic fluid exerted within thecylinders 22 and 24, and when such pressure reaches a predeterminedlevel thereby indicating that the section 300 is rigidly clamped betweenthe clamping member 54 of the assembly 46 and the die 70 and that thecutting member 48 has been moved downwardly whereby the section has beencut into a disk, the pressure switch 217 closes or otherwise sends anelectric signal to the electric control system whereby the second phaseof the manufacturing operation is commenced.

The second phase of the manufacturing operation involves forming aconcave-convex dome in the section 300 which has previously been cutinto a disk. This is accomplished by the opening of the valve 202 (FIG.9) whereby pressurized fluid, preferably pressurized air, is caused toflow from a source thereof by way of the conduit 200, through the valve202 and the conduit 204, through the passages 122 and 124 in the ram 102and through the passage 120 in the plate 116 of the blade assembly 114.Referring now to FIG. 11, the O-ring 66 provides a seal between the topface of the clamping member 54 and the bottom surface of the platform 30and the O-ring 110 provides a seal between the member 104 and theoutside surface of the ram 102. Thus, the space between the top surfaceof the sheet metal disk 300 and the plate 116 of the blade assembly 114is sealed and the pressurized fluid flowing into the space by way of thepassage 120 creates a force on the top side of the disk 300. Thepressurized fluid forces the disk 300 downwardly against the surface ofthe dish-shaped recess 82 in the forming face of the die 70 as shown inFIG. 11. The passage 88 in the die 70 allows air trapped between thebottom surface of the sheet metal disk 300 and the surface of the recess82 to escape as the disk is forced against and conformed to the formingface of the die 70 whereby a concave-convex dome is formed therein.

Referring again to FIG. 9, after the pressurized fluid has been appliedto the sheet metal disk 300 for a predetermined period of time, thevalve 202 is shut off and the valve 208 is opened whereby pressurizedfluid within the space between the blade assembly 114 and sheet metaldisk 300 is exhausted by way of the passages 120, 122 and 124, theconduit 204, the conduit 206, the valve 208, the conduit 210, theorifice assembly 212 and the conduit 214. However, because the orifice212 restricts the flow of pressurized fluid therethrough, the fluidpressure exerted on the sheet metal disk 300 within the apparatus 10 isexhausted therefrom slowly.

While fluid pressure is being applied to the disk 300, the hydrauliccontrol valve 192 is activated whereby hydraulic fluid flows by way ofthe conduit 206 to the valve 192 and through the conduit 188 into thetop port of the hydraulic cylinder 96. This causes the piston within thecylinder 96 to move downwardly which in turn causes hydraulic fluid toflow through the lower port of the cylinder, through the conduit 194,through the valve 192 and into the hydraulic fluid return system by wayof the conduit 210. As the lever arm 98 of the cylinder 96 movesdownwardly, the plate 100 and ram 102 attached thereto also moveddownwardly whereby the blade assembly 114 attached to the ram 102forceably contacts and forms scores in the concave-convex dome portionof the disk 300 as shown in FIG. 11.

Prior to forming the disk 300, the microbar assemblies 130 and 132 areeach adjusted in height so that the desired depth of score is formed inthe disk 300 and the blade assembly 114 is prevented from being damaged.That is, the bottom surface of the plate 100 contacts the microbarassemblies 130 and 132 immediately after the blade assembly 114 contactsthe disk 300 whereby scores of desired depth are formed on the disk 300and the blade assembly is prevented from moving downwardly too farwhereby it forceably contacts the die 70 and damages the die 70 or theblades 118. When the apparatus 10 is utilized to form rupture disks withperforations therein, i.e., the blade assembly attached to the ram 102perforates the disk, the microbar assemblies 130 and 132 are set suchthat the blades of the blade assembly perforate the disk but do notcontact the forming face of the die 70 in a manner whereby damage to thedie or the blade assembly results. As previously described, the heightof the microbar assemblies 130 and 132 is adjusted by rotating the knobs152 and shafts 150 (FIGS. 7 and 8) whereby the members 140 are movedlaterally with respect to the base members 132 thereof.

After the scores have been formed in the disk 300, the blade assembly114 is maintained in forceable contact with the concave-convex domeportion of the disk 300 for a period of time, i.e., for a predetermined"dwell time". The pressure switch 218 (FIG. 9) attached to the conduit188 senses the hydraulic fluid pressure in the top portion of thecylinder 96, and when the pressure reaches a predetermined level thehydraulic fluid flow into the cylinder is stopped to thereby control themaximum score blade force exerted on the disk 300.

The hydraulic control valves 182 and 192 are next activated whereby theflow of hydraulic fluid to the cylinders 22, 24 and 96 is reversed andthe platform 30 as well as the ram 102 and plate 100 are moved upwardlyto their uppermost positions. The rupture disk 300 formed by theapparatus 10 having the shape and form illustrated in FIGS. 12 and 13 isremoved from the apparatus 10 and replaced with a new flat sheet metalsection whereupon the manufacturing process is repeated to form anotherrupture disk, etc.

Referring once again to FIG. 9, the pressure switch 216 senses thehydraulic fluid pressure in the system downstream of the pressureregulator 202. If the pressure becomes too high for any reason, i.e.,above a predetermined set point, the switch 216 closes and causes thevalve 214 to open whereby pressure is relieved from the system. Othersafety controls which will suggest themselves to those skilled in theart can also be used in the apparatus 10.

As shown in FIGS. 12 and 13, the rupture disk 300 produced includes anannular flat flange portion 301 connected to a concave-convex domeportion 303 by an annular transition connection 305. The annular flatflange portion 301 includes three locating holes 302 for receivinglocating pins which are positioned in a predetermined pattern wherebythe disk 300 cannot be installed upside down and the concave-convexportion 303 includes four scores 304 positioned in a cross patternwhereby the scores extend radially outwardly from a central portion tothe periphery of the dome portion.

As will be understood, both the rupture disk forming die 70 and thescore forming blade assembly 114 can be removed from the apparatus 10and replaced with other rupture disk forming dies and score orperforation forming blades to produce rupture disks of differentconfigurations containing different score or perforation patterns. Forexample, as shown in FIG. 14, a rupture disk 400 having the sameconfiguration as the rupture disk 300 can be produced except thatinstead of a cross score pattern formed by four straight line scores,the rupture disk 400 includes a single score 402 forming a partialcircle in the concave-convex dome portion thereof.

A rupture disk 500 having yet another score pattern formed in theconcave-convex dome portion thereof is illustrated in FIG. 15. That is,the rupture disk 500 contains three scores 502 which form a patterncomprised of two opposing arcs of a circle connected at intermediatepoints by a straight line score.

FIG. 16 illustrates a perforated rupturable member 600 which can beformed by the apparatus 10 having a concave-convex dome portion whichincludes perforations 602 formed therein, i.e., triangular cut-outswhereby crossing straps 604 remain.

FIG. 17 illustrates an alternate form of perforated rupturable memberwherein the perforations form a plurality of apertures 702 connected byslits 704 extending radially outwardly from a central portion of theconcave-convex dome portion of the disk to the periphery thereof.

FIG. 18 illustrates yet another form of perforated rupturable member 800wherein the perforations are in the form of four slits 802 extendingradially outwardly from a central portion of the disk.

A variety of other rupture disks, rupturable members, vacuum supportsand other disk products can be produced in accordance with the method ofthe present invention utilizing the apparatus 10.

In forming all of the variety of disk products which can be formed withthe apparatus 10, a concave-convex dome is first formed in a sheet metaldisk by applying pressurized fluid to one side thereof followed byforming the scores or perforations in the concave-convex dome of thedisk while continuing to apply pressurized fluid thereto. This isaccomplished in the apparatus 10 by forceably contacting theconcave-convex dome of the disk 300 with the blade assembly 114 (FIG.11) prior to or immediately upon the opening of the valve 208 whichexhausts the pressurized fluid from the apparatus 10. Because of theorifice assembly 212 or other equivalent flow restriction means in thepressurized fluid exhaust flow path, pressurized fluid remains in theapparatus 10 after the scores or perforations are formed on the rupturedisk being produced. This in turn reduces the stresses produced in thedisk by the scoring or perforating. In addition, after the bladeassembly attached to the ram 102 is brought into forceable contact withthe rupture disk being produced to form the scores or perforationstherein, the blade is preferably maintained in forceable contact withthe disk for a predetermined dwell time. This again reduces the stressesformed in the disk and allows the metal of the disk to become wellsettled in its new shape before the various forces exerted on it areremoved.

Because the scores or perforations formed in the disk are formed whilefluid pressure is maintained on the disk and because the score orperforation forming blade is maintained in forceable contact with thedisk for a dwell time, the rupture disks produced by the method of thisinvention in the apparatus 10 have fewer stresses therein and generallydo not require annealing to relieve stresses. This reduction orelimination of the requirement for annealing reduces the manufacturingcost of the rupture disks produced and allows rupture disks to beproduced which are formed of metals which could not heretofore beutilized because they could not be annealed. Examples of such metals aresilver, tantalum, titanium and platinum.

The blade assembly of the apparatus 10 forms all of the scores orperforations produced in the rupture disks being manufactured at onetime, which makes the scores or perforations more uniform in depth,width and other characteristics and the scores or perforations are moreprecise in configuration and orientation than those formed using priormanufacturing methods, all of which brings about a superior rupture diskproduct. In addition, because of the use of the microbar assemblies 130and 132 in combination with the rest of the apparatus 10, more precisecontrol of variables can be accomplished which in turn brings about themanufacture of rupture disks having better operational characteristicsthan heretofore possible.

Thus, the method and apparatus of the present invention are well adaptedto carry out the objects and attain the ends and advantages mentioned aswell as those inherent therein. While presently preferred embodiments ofthe invention have been described for purposes of this disclosure,numerous changes can be made in the construction and arrangement ofparts, which changes are encompassed within the spirit of this inventionas defined by the appended claims.

What is claimed is:
 1. An improved method of manufacturing a rupturedisk containing one or more scores or perforations from a sheet metalsection comprising the steps of:cutting said section into a disk;forming a concave-convex dome in said disk by applying pressurized fluidto one side thereof; and forming said one or more scores or perforationsin the concave-convex dome of said disk while continuing to applypressurized fluid thereto.
 2. The method of claim 1 wherein at least twolocating holes positioned near the periphery of said disk are punchedtherein substantially simultaneously with the cutting of said sectioninto a disk.
 3. The method of claim 1 wherein the pressurized fluid ispressurized air.
 4. The method of claim 1 wherein the step of formingsaid one or more scores or perforations in the concave-convex portion ofsaid disk comprises:forceably contacting said concave-convex domeportion of said disk with a score or perforation forming blade;maintaining said blade in said forceable contact with saidconcave-convex dome portion of said disk for a period of time; and thenremoving said blade from contact with said disk.
 5. An improved methodof manufacturing a scored rupture disk from a sheet metal sectioncomprising the steps of:clamping said sheet metal section over a centralconcave-convex dome forming die; cutting said section into a disk whileclamped over said die; applying pressurized fluid to the side of saiddisk opposite said die whereby the central portion of said disk isconformed to said die and formed into a concave-convex dome; and movinga convex score forming blade into forceable contact with the concaveside of said concave-convex dome portion of said disk while said disk isclamped over said die and while said pressurized fluid is applied tosaid dome portion thereof to thereby form scores in said disk.
 6. Themethod of claim 5 wherein said die includes an annular flange formingportion surrounding said central concave-convex dome forming portion. 7.The method of claim 6 wherein an annular flange portion of said sheetmetal section is clamped to said annular flange forming portion of saiddie and said method is further characterized to include the step ofpunching at least two locating holes in said annular flange portion ofsaid sheet metal section.
 8. The method of claim 7 wherein said locatingholes are punched in said annular flange portion of said sheet metalsection when said section is clamped over said die.
 9. The method ofclaim 5 wherein said score forming blade is maintained in forceablecontact with said disk for a period of time after forming said scoresthereon.